Talk:GWR 4100 Class

Prototype 4-4-0 locomotives: names
The names given for two locos don't agree with those in le Fleming (p. G29) - this book has 16 & 4169 Charles Saunders, 14 & 4170 Brunel. However, "Names, Numbers, Types and Classes" has 16 Brunel, 14 Charles Saunders in the 1911 edition; the 1928 edition has 4169 Brunel, 4170 Charles Saunders. -- Red rose64 (talk) 22:27, 11 October 2012 (UTC)
 * I changed the names based on Nock- haven't got the le Fleming to check, so I left the ref in. Photographs in vol 1 of Nock (p 12, p 14 and p 92, confirm 14 for Charles Saunders and 16 for Brunel, but there's no such confirmation for the renumbered locos. Ning-ning (talk) 03:24, 12 October 2012 (UTC)
 * Just found an auction listing (and illustration) for a glass negative of 4169 Brunel. Ning-ning (talk) 03:55, 12 October 2012 (UTC)
 * And this allegedly shows 4170 Charles Saunders with 7 foot wheels; doesn't look like the splashers have been changed, whereas they had on the photo of 4169. Ning-ning (talk) 09:48, 12 October 2012 (UTC)
 * OK, I've checked out
 * This book gives corrections to the earlier volumes: it seems that le Fleming transposed the two names on p. G29, so it's definitely 16 & 4169 Brunel, 14 & 4170 Charles Saunders. If you have parts 13 & 14 of the RCTS series, note that although these do list corrections, they don't incorporate those corrections given in part 12. Apparently part 12 is the scarcest of the fourteen. -- Red rose64 (talk) 20:32, 12 October 2012 (UTC)
 * Thanks. Would be nice to get a more detailed description of the various changes made to these locos; it seems a bit odd to change the cylinders and valves and then reduce the driving wheel diameter by 4 inches, thus throwing out the aligment of cylinder and driving centre. Ning-ning (talk) 22:14, 12 October 2012 (UTC)
 * Churchward was hot on standardisation: this didn't mean that new locos should be of a limited number of designs, but that as far as possible, different classes - both new and existing - should share components, in order to minimise the quantity of spare parts which had to be stocked (not just at Swindon, but at the larger running sheds too).
 * This policy included spare wheel tyres, and so he wanted to keep the number of different sizes of wheel to a minimum. He therefore chose a few of the sizes already in use - generally the more common ones - and restricted newly-built locos to those sizes. So new Churchward locos used just four sizes - 4 ft, 4 ft, 5 ft and 6 ft; and whilst there were many existing locos with 5 ft wheels (such as the Dean Goods), Churchward kept suitable tyres in stock but didn't build new locos with that wheel size (although Collett did). Those sizes which were used on only a few locos were excluded from the list of standard components - and so those locos using the more obscure sizes would eventually need to have their wheels exchanged for a standard size, unless the loco was to be scrapped.
 * The Armstrong class used a 7 ft wheel, not used on any other coupled loco on the GWR - and the only other locos using this size, after the end of the broad gauge, were some 2-2-2, the newest of which were the 157 Class (built 1878-79). Assuming a thirty-year design life (by no means unusual at that date), these would all be gone by the end of 1909, so the four locos of the Armstrong class - sixteen wheels in all - would be the only requirement for the 7'0" size after that date. In fact the last two 7'0" singles - no. 1128 of the Queen class and no. 165 of the 157 class - went in 1914, so it then made economic sense to exchange the 7'0" wheels on the Armstrong class for the nearest standard size, i.e. 6 ft, as and when the tyres became due for replacement (1915-23). -- Red rose64 (talk) 00:05, 13 October 2012 (UTC)
 * The Armstrong class used a 7 ft wheel, not used on any other coupled loco on the GWR - and the only other locos using this size, after the end of the broad gauge, were some 2-2-2, the newest of which were the 157 Class (built 1878-79). Assuming a thirty-year design life (by no means unusual at that date), these would all be gone by the end of 1909, so the four locos of the Armstrong class - sixteen wheels in all - would be the only requirement for the 7'0" size after that date. In fact the last two 7'0" singles - no. 1128 of the Queen class and no. 165 of the 157 class - went in 1914, so it then made economic sense to exchange the 7'0" wheels on the Armstrong class for the nearest standard size, i.e. 6 ft, as and when the tyres became due for replacement (1915-23). -- Red rose64 (talk) 00:05, 13 October 2012 (UTC)